Where there’s smoke, there’s air quality scientists

NIWA scientists are now analysing data gathered from an air quality pilot experiment in Rangiora that could revolutionise the way communities can measure and control pollution.

During September, NIWA staff installed temperature sensors in 14 homes in the North Canterbury town to detect when the occupants were using their woodburners. At the same time six prototype low-cost dust sensors, called ODINs or Outdoor Dust Information Nodes developed by NIWA, were installed on lamp posts around Rangiora to test their robustness and data quality.

If successful, air quality scientist Dr Ian Longley said the sensors could be a game-changer in being able to identify pollution problems and their causes and enable communities to work with councils on coming up with solutions.

Dr Longley said the data was now being analysed to determine whether different parts of Rangiora have different air quality and how that air quality varies from day to day.

The first stage of the pilot project had been a great success and Dr Longley said he was particularly grateful for the enthusiasm of the study’s participants.

“Despite a few glitches which you would expect in any pilot, our dust sensors have performed well, and provided us with some consistent and valuable data. This will enable us to further develop this project before the second field test next winter.”

In addition to the ODINs, temporary meteorological stations were set up around the outskirts of Rangiora to track changes in wind speed and direction while other measurements of air rising above the town, were also undertaken.

Preliminary results observed by the scientists so far have shown:

There is a variation in the amount of woodsmoke across Rangiora but what’s causing that variation is not yet clear.

The temperature outside Rangiroa’s boundaries is slightly lower than in town

When participants started their wood fires, the temperatures inside their homes rose at different rates. Some homes warmed up at 2°C per hour, while some warmed at about 10°C per hour.

About midnight the air in each house starts to cool and again there was some variation in how fast that occurred.

Scientists are beginning to understand the trigger points for people to light their woodburners, or when they stop using them.

“With the help of our local participants we installed 27 temperature sensors, 11 indoor and 6 outdoor air quality sensors. With the meteorological measurements we made too that’s millions of datapoints to interpret.

“Now we’re moving into the next phase of the research. From these data, and with the continued help of our volunteers, we will carefully construct the story of air quality in one of our country towns to a level of detail that has never been possible before.”

The study participants will be given information about the project as it is analysed and their feedback will be important in evaluating how it went and how to best present the information to encourage people to become more aware of air quality issues.

Next year the scientists plan a follow-up project in Rangiora and to expand to larger towns.

“The long term goal is to predict air quality and how management options can influence and change it,” Dr Longley said.